Sharpening machine



T. H. SMITH SHARPENING MACHINE Aug. 21, 1951 5 Sheets-Sheet 1 Filed May 9, 1949 INVFNTOF T. /7. 5/77/29? BY W ATTORN E Aug. 21, 1951 s rr 2,564,796

SHARPENING MACHINE Filed May 9, 1949 3 Sheets-Sheet 2 Jazz 2/ Lfli ATTOR N EY INVENTOR.

T. H. SMITH SHARPENING MACHINE 3 sheets sheet 5 Filed May 9, 1949 INVENTOR. 7? 'H. S m/ 2 h BY v W ATTORNEY Patented Aug. 21, 1951 UNITED STATES PATENT OFFICE sHARPENmc. MACHINE Thomas H. Smith, Oklahoma City, Okla.

Application May 9, 1949, Serial No. 92,211

This invention relates to a sharpening machine, and more particularly to a machine for sharpening lawn mowers. 1

The object of the invention is to provide a machine which will insure an accurate grinding and sharpening of the cutting blades of lawn mowers.

Another object of the invention is to provide a lawn mower sharpening machine which includes a power driven grinding wheel that is caused to move longitudinally along the blades, under the control of the operator, to sharpen the blades.

Still another object of the invention is to provide a lawn mower sharpener which includes a support for the mower reel, there being manually operable means for adjusting the support vertically and horizontally to insure a correct alignment or centering between the grinding wheel and the cuttin blades being sharpened.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is a front elevational view of the lawnmower sharpener, with parts broken away, according to the present invention;

Figure 2 is an end elevational view of the machine;

Figure 3 is a fragmentary elevational view of the other end of the machine;

Figure 4 is an enlarged sectional view taken on the line 4-4 of Figure 2;

' Figure 5 is an enlarged sectional view taken on the line 55 of Figure 1;

Figure 6 is an enlarged sectional view taken on the line 6-6 of Figure 1; and

Figure 7 is an enlarged sectional view taken on the line l--l of Figure 2.

Referring in detail to the drawings, the numeral 20 designates a table and the table includes a horizontally disposed platform 2 I, and for supporting the platform 2|, there is provided a plurality of vertically disposed spaced parallel legs 22. Extending longitudinally across the top of the platform 2| and secured thereto is a bed plate 23 which is provided with a longitudinally extending slot 24, Figure 6, in its upper end. Rotatably supported in the bed plate 23 and extending longitudinally therethrough, is a first horizontally disposed shaft 25 which has a slot l9 extending longitudinally along its exterior surface. One end 26 of the shaft 25 projects beyond the bed plate 23 and the end'26 is squared,

2 Claims. (01. 51-36) 2 Figure 1, for receiving the socket of a crank 21 (dotted line) whereby the shaft 25 can be manually rotated for a purpose to be later described.

Projecting upwardly from the bed plate 23 is a pair of spaced parallel vertically disposed sup port members 28 and 28', and each of'the support members 28 and 28' has the same construction. Secured to the bottom of the support member 28 or 28' is a horizontally disposed base 29 which is slidably supported on the bed plate 23. A headed stud or bolt 30 projects through the base 29 of the support member and the bolt 30 is arranged in threaded engagement with a T- nut 3| for maintaining the support members28 and 28 immobile in their adjusted position. Thus, to adjust the support members 28 and 28 the bolt 30 is loosened, whereby the support members can be moved to the desired location on the bed plate 23 and the bolt 30 can then be tightened in the nut 3l to prevent movement of the support member.

Dependingly carried by the base 29 is a leg 32 which slidably projects through the slot 24 in the bed plate 23 and the leg 32 is provided with a central aperture for the projection therethrough of a collar 33. A key 34 projects from the collar 33 and into engagement with the slot IS in the shaft 25 so that rotation of the shaft 25 causes rotation of the collar 33. A vertically disposed bevel gear 35 is secured to the collar 33, and the bevel gear 35 is arranged in meshing engagement with a horizontally disposed bevel gear 36. The bevel gear 36 is secured to the lower end of an exteriorly threaded shaft or screw 31, the screw 31 being vertically dis-posed. The screw 31 is arranged contiguous to the support member 28 while a similar screw 31' is arranged contiguous to the other support mem ber 28'.

Each of the support members 28 and 28' is provided with a longitudinally extending key 38 which is arranged in sliding engagement with a recess or channelway 39, the recess 39 being formed in a T-shaped body member 40. The body member 40 includes a horizontally disposed projecting leg 4| and a vertically disposed portion 42 which is arranged contiguous to the complemental support member. A pair of brackets 43 are secured to the vertically disposed portion 42 of the body member 40 by securing elements 44 and the brackets 43 maintains the body mem,- ber 40 in sliding engagement with the proper support member. The vertically disposed portion 42 of the body member 40 has secured thereto a collar 45 which is provided with an interiorly threaded bore 46, and arranged in threaded ngagement with the bore 46 is the previously described threaded screw or shaft 31 or 31. Thus, upon manual rotation of the shaft 25 by the crank 21, the screws 31 and 31' are rotated whereby the support members 40 are raised and lowered vertically depending upon the direction of rotation of the shaft 25.

Each of the horizontally disposed legs 4| of the body members 40 are provided with a projecting longitudinally extending key 41 which slidably registers with a channelway or recess 48 which is arranged in a plate 49. The plate 49 is slidably arranged contiguous to the horizontally disposed leg 4|. Secured to the plate 49 or formed integral therewith, is a collar 50 which is threaded interiorly as at 5|, Figure '7, and arranged in threaded engagement with the interiorly threaded collar 59 is a horizontally disposed screw or exteriorly threaded shaft 52. A bracket sa is transected to the plate 49 by means of a piuraiay of rivets or screws 54, and the bracket 53 maintains the plate 49 coritiguoiisto and in sliding engagement with the 143g 41. Secured to the'upp'er of the plate 49 is a boss 55 which provided with an opening '55'therein for receiving an end of a lawnmower reel 51, ddtte'd line's, -jF'igure'Z. Thus, the mower reel 51, which contains the lawnmower cutting blades, is supported by the pair of bosses 55 and'the reel 51 can be adjusted vertically and horizontally to insure a correct and accurate sharpening of the cutting blades.

There are two of the horizontally disposed screws '52, "so that the plate 49 on each of the body members '48 can be adjusted horizontally. Secured to the rear end of each of the pair of horizontallydisposed screws '52 is a'bevel gear-5 8 and the bevel gear 58 is arranged in meshing engagement with a bevel gear 59 which is mounted on a shaft 68. The shaft 88 is horizontally disposed and is rotatable, and the shaft 68 has keyed thereon a pair of the bevel gears 59 so that upon rotation of the shaft 5|], both of the screws 52 are rotated to thereby adjust the horizontal .pos'itiono'f the mower reel 51. An end 6| o'f theshaft 88 is of square cross section for engagementwith'the' socket of the crank 21 whereby the shaft 58 can be'manually rotated.

Projectin upwardly from the ends Of the plat- Io'rn'i 2| of the "table '25 is a pair of vertically dispose'dspaced parallel frames 52 and 53, the frames being secured to the platform 2|. The irames szantits suppcrt a horizontally disposed crossbar 84 which is secured to the tops thereof. A carriage 651s mounted for longitudinal sliding movement amng the machine and the carriage 65 includes abase What is arranged in sliding engagement with the cross bar 85. Supported by the rear end of each of the frames 62 and 63 is a bearing'block '81 and the bearing blocks 51 support a horiz'on'tally disposed rotatable shaft 68 which is provided with a longitudinally extending slot 89-the'rein for a purpose to be later described. Supported on the table 28 is a motor 18 which'is adapted'to be connected to a suitable source of electrical energy, and the motor 18 rotates a drive shaft 1| which has a pulley 12 mounted thereon; A pulley '13 is mounted on the projecting end of the shaft 68 and a'belt 14 is trained between the pulleys 12 and 13 so that upon actuation of the motor 18, the shaft 68 is rotated.

Carried-by the rear .portion' or the carriage 55 is a pulley 15 which is provided with a key 16 that projects into the slot 69 in the shaft 68. The pulley 15 is rotatable, so that upon rotation of the shaft 68, the pulley 15 is caused to rotate therewith. Projecting forwardly from the carriage 65 is a pair of bearing arms 11 and 18 which support a rotatable shaft 19 therein. Mounted on the shaft 19 and interposed between the bearing arms 11 and 18 is a grinding or sharpening wheel 89 which may be made of a suitable abrasive material. A pulley 8| is mounted on the shaft 19, and trained between the pulley 8| and the pulley 15 is a belt 82 so that rotation of the shaft '88 causes the grinding wheel 88 to be rotated to thereby sharpen the cutting blades 01' the lawnmower reel.

Rotatably supported by the frame 52 is a short shaft 83. A pulley 84 is mounted on the shaft 83, and there is mounted a pulley 85 on the corresponding end of the shaft 68. Trained between the pulleys 8'4 and '85 is a belt '88. Rotatably supported by the frames 62 and 83 is a horizontally disposed shaft 81 which carries a pulley 88 on one end thereof. A pulley 89 is arranged in alignment with the pulley 88 and is mounted on the short shaft 83, and a suitable belt '88 is trained between the pulleys 88 and 89 so tha'trotatioh or the shaft 68 causes rotation of th'e'shaft -83 and this in turn rotates the shaft 81.

The shaft 81 is threaded exteriorly for a major portion of its length as at 9|, Figure 1, and a tapped yoke 92 of a clutch 93 is mounted for movement into and out of engagement with the threaded portion 9| of the shaft 81. The clutch 93 is pivotally mounted on a pin 94 which is supported by the carriage -85. Thus, when the clutch '93 is mo'ved from the dotted line position of Figure 5 to the'solid line position, the yoke '92 moves into engagement with the threaded portion 9| of the shaft "8? so that the carriage '65 is caused to move longitudinally along the machine, thereby causing the cutting blades to be sharpened along their entire length.

The operation of the machine is as follows'i The 'lawnmowjer reel 51 is supported by the pair'of bosses 55 as shown in Figure 2. Then, the crank 21 is arranged in engagement with the square end '28 of the shaft 25 and the shaft'25 is rotated to thereby rotate the bevel gears 35. Rotation 'of'the bevel gears 35 causes the bevel gears 36 to rotate whereby the screws 31 are turned to thereby'ra'ise or lower the body members 40 on .the support members 28 and 28'. Thus, by rotating the shaft 25, the .mower reel 51 can be adjusted to the correct vertical posi-- tion relative to the grinding wheel 80. A means is also provided for adjusting the mower .reel 51 horizontally 'to' insure a correct alignment of the grinding reel 88 and the mower reel 51. Thus, this horizontal adjustment is accomplished by arranging the crank '21 in engagement with the square end SI of the shaft andthenvupon rotation of the-crank '21, the shaft 68 is rotated. Rotation of the shaftlifl causes rotation of the bevel gears 59 which in turn rotate 'the meshing bevel gears 58 and this results in a rotation of the pair of adjusting screws 52. Rotation of the adjusting screws 52- results in movement of the plates le-along the legs 4| of the body members 49, so that'the mower reel 51 can be adjusted to the desired horizontal position. After the mower reel '51 has been adjusted to the correct position,'the -motor"10 is actuated and the motor 19 drives the shaft H which in turn rotates the shaft 68. Rotation of the shaft 68 causes the pulley 15 to rotate, since the pulley I5 is keyed, as at 16, to the shaft 68. Rotation of the pulley 15 causes the grinding wheel an to turn or evolve so that the cutting blades will be evenly and accurately sharpened. Further, the grinding wheel 80 moves longitudinally along the cutting blades to sharpen the latter. A means is provided for causing longitudinal movement of the grinding wheel 80. Thus, as the shaft 68 rotates it causes the short shaft 83 to rotate which in turn drives the horizontally disposed shaft 81. Then, with the shaft 81 rotating, the clutch 93 is moved from the dotted line position of Figure 5 to its solid line position whereupon the tapped yoke 92 moves into engagement with the threaded portion 9| of the shaft 81 so that the carriage 65 moves longitudinally along the machine.

From the foregoing it is apparent that a lawnmower sharpening machine has been provided which will insure an accurate sharpening of the cutting blades of lawnmowers. The mower reel 51 can be adjusted verticallyand horizontally to insure that the cutting blades thereof will be accurately sharpened and the machine is easily to operate. The clutch 93 is readily accessible to the operator and the machine is constructed so that long smooth operation thereof is insured.

What I claim:

1. In a sharpening machine for lawn mower blades, an elongated rectangular base, an open frame rising from said base at one side of its longitudinal center, a carriage mounted for movement on and endwise of said base, an abrasive wheel mounted on said carriage in ofi'set relation with respect to the inner side of the same and the like side of said frame, a screw shaft journalled in the opposite ends of the top side of said frame, a clutch lever pivoted intermediate its ends on said carriage, a toothed quadrant mounted on the carriage, a pawl pivoted on said lever for cooperation with said quadrant, an arcuate clutch member formed on the lower end of said lever for engagement with the screw thread of said shaft, power means for rotating said abrasive wheel, and adjustable means on said base at the opposite side of its longitudinal center for supporting a mower blade unit in position for the sharpening of a blade thereof by said abrasive wheel as the carriage is moved along said frame.

2. The invention as defined in claim 1,,with the said adjustable means comprised in an inverted U-shaped bed on said base and coextensive with said frame, said bed having a slot extending longitudinally of its top side, a first shaft extending through said bed below and in line with said slot, bearings at the opposite ends of said bed for said shaft, said shaft being longitudinally slotted and having one of its ends squared, angled brackets slidably mounted on said shaft, a vertical member rising from each of said brackets, a screw shaft disposed alongside of each of said members and having its lower end depending therethrough, a bevel gear keyed on the lower end of each of said screw shafts, a second bevel gear slidably keyed to said first shaft and journalled in the adjacent bracket in meshed relation with the first gear, a T-shaped member having its head portion slidably mounted on each of the first members and its leg portion extending horizontally outwardly therefrom, a collar ofiset from the lower side of the leg portion of each of said T-shaped members and engaged with the complemental of said screw shafts, a plate slidably bracketed on each of said leg portions, a bearing mounted on the upper side of each of said plates for the support therein of an end of a mower blade unit, a collar offset from the outer side of each of said plates, a screw shaft extended parallel to each of said leg portions and threaded through each of the last named collars, a hearing bracketed on the inner side of each of said head portions, a second longitudinally slotted shaft journalled in the last named bearings, meshing gears between the latter shaft and each of the last named screw shafts, the gears on the said second shaft being slidably keyed thereto, said second shaft having one of its ends squared, and a hand crank engageable with the squared ends of the said first and second shafts.

THOMAS H. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 411,095 Dooley Sept. 17, 1889 595,125 Kirsten Dec. 7, 1897 1,344,168 Brown June 22, 1920 1,389,588 Klay Sept. 6, 1921 1,409,641 Anderson Mar. 14, 1922 1,448,518 Brown Mar. 13, 1923 1,916,063 Miller June 27, 1933 1,967,964 Miller July 24, 1934 2,142,669 Carpenter Jan. 3, 1939 2,432,851 Anderson Dec. 16, 1947 

